DIY_EFI Digest Monday, 11 November 1996 Volume 01 : Number 342 In this issue: RE: Prom Burners O2 sensor (Ford) Forwarded: Re: O2 Sensor Open/Close Loop re: O2 sensor (Ford) Forwarded: RE: O2 Sensor Open/Close Loop What is the story with Synth-Oil Air Temperature Effect Motronic Re: Air Temperature Effect See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: john spears Date: Sun, 10 Nov 96 12:22 EST Subject: RE: Prom Burners George and Jen ask about which prom burner to use for the 1227730 ECM on a TPI conversion. The EPROM used on this application is a 27256 (32K X 8), so there are many programmers to choose from that will support this device. I use a Data I/O 29B, but there are many others too. BTW the 1227730 is NOT an SFI controller, as stated in your post. It is a batch fire controller. John Spears Speartech Fuel Injection Systems ------------------------------ From: "M. Brede Moe" Date: Sun, 10 Nov 1996 21:18:41 +0100 Subject: O2 sensor (Ford) It has been interesting to follow the O2 sensor thread. I've got a problem with my '89 Ford using the 3-wire type HEGO sensor and the EEC-IV that perhaps some of you are able to comment. Earlier this year, I replaced the sensor because of a code 41 (always lean). This because I coudn't find any other plausible reason for the error, the sensor was just black from soot and did not have the miscolored tip indicating some kind of contamination. Worked fine for some months, now I am back with the code 41. The 'Check Engine' will start flashing on each trip after engine warm-up. This system depends on signal return via the exhaust system, which obviously makes room for errors if you have bad electrical grounding. When measuring the sensor signal with a high-impedance analogue meter, I occasionally see some negative swings of the needle. I also measure some .25V between battery negative and the sensor casing. My question is really if these kind of voltages in the ground path can actually kill the sensor? It would also be interesting to know how the sensor signal is treated inside the EEC-IV. The shop manual says that pin 49 is HEGO return, which is connected to engine ground externally. Does anyone know how this is related to chassis ground or battery negative internally? If pin 29 (HEGO input) and 49 makes up a differential input, it would be tempting to replace the sensor with a 4-wire unit. Are these sensors mechanically and electrically compatible except for the extra wire? The 3-wire (Bosch) replacement sensor from Ford cost about $200 here, which makes it more economical to pay for the extra gas in open loop mode rather than replacing the sensor 3-4 times a year... The exhaust is still within spec's. Regards, M. Brede Moe - -- - - mamoe@xxx.no ------------------------------ From: RABBITT_Andrew@xxx.au Date: Mon, 11 Nov 1996 08:27:20 est Subject: Forwarded: Re: O2 Sensor Open/Close Loop WOT calibration (as with the rest of the base fuelling maps) are all normally done on an engine dynamometer. From: (Mark Mason) mmason@xxx.com:smtp Date: ## 11/09/96 10:47 ## tom cloud wrote: > > I don't know for sure, but some calculation has to be made (is > it basically in speed-density mode ??? at WOT ???) Clearly, if > it's already speed-density, then it just goes with whatever calcs > or maps are set up for it. What do the OEM guys use to setup the map values for pulse vs RPM vs temp vs load? Mark Mason ------------------------------ From: RABBITT_Andrew@xxx.au Date: Mon, 11 Nov 1996 08:34:28 est Subject: re: O2 sensor (Ford) >It would also be interesting to know how the sensor signal is treated >inside the EEC-IV. The shop manual says that pin 49 is HEGO return, >which is connected to engine ground externally. Does anyone know how >this is related to chassis ground or battery negative internally? If >pin 29 (HEGO input) and 49 makes up a differential input, it would be >tempting to replace the sensor with a 4-wire unit. The EEC-4 in some European Fords use a 4-wire sensor. I can't quote pin #'s off the top of my head but I can't see why this wouldn't work. > >Are these sensors mechanically and electrically compatible except for >the extra wire? Mechanically yes, (they will screw into the same hole). Electrically, most probably. ------------------------------ From: RABBITT_Andrew@xxx.au Date: Mon, 11 Nov 1996 08:13:14 est Subject: Forwarded: RE: O2 Sensor Open/Close Loop TWC = three-way catalyst, means that it oxidises HC and CO and reduces NOx. Sorry for the TLA. From: (tom cloud) cloud@xxx.edu:smtp Date: ## 11/08/96 11:35 ## [ snip ] >I think you'll be hard-pressed to find a production car with a EGO but >no TWC, they go hand in hand. It has next to nothing to do with fuel >consumption since you want to go lean to improve this. > >Andrew Rabbitt Okay, Andy, what's "TWC" ?? Tom Cloud ------------------------------ From: Dimos Katsis Date: Sun, 10 Nov 1996 22:40:19 -0500 (EST) Subject: What is the story with Synth-Oil I am interested in any opinions on the pros and cons of using synthetic oil instead of regular crude. I know that this is not the Car-Talk radio show but it would be interesting to see what fellow engineers think. Thanks Dimos K. ------------------------------ From: Doug Robson Date: Mon, 11 Nov 1996 15:06:08 +1100 Subject: Air Temperature Effect Hi ALl anyone got any stats on the effect of air temperature of charge in FI normally aspirated engines. ?? - -- |===============================================================| | When I die, | | I want to go in my sleep, like my grandfather, | | not screaming like the passengers in his car. | |---------------------------------------------------------------| | Doug Robson (H) mailto:doug@xxx.au | | (W) mailto:Doug.Robson@xxx.com | | Sydney, Australia http://www.cia.com.au/doug | |---------------------------------------------------------------| | Club Car Racing Register of NSW | Thank God | | 1992/93 Under 2 litre State Champion | for | | http://www.cia.com.au/doug/ccrrnsw.html | Gravity | |===============================================================| ------------------------------ From: "Bosch, AN, Andrew, Dr" Date: Mon, 11 Nov 1996 09:48:05 UTC-2 Subject: Motronic Hi. Can someone give me some info about the Motronic system as used on 1984 BMW 735's, particularly, is it feasable to take the system and install it in a vehicle that currently has an L-Jet system ie. can one re-programme (map) it to make it work in another application? If so, how!? Thanks in advance. Andrew Dr A. N. Bosch Physiology Department/ Sports Science Institute University of Cape Town Medical School P. O. Box 115 Newlands 7700 South Africa ------------------------------ From: jon hanson Date: Mon, 11 Nov 1996 09:15:18 +0200 Subject: Re: Air Temperature Effect At 15:06 11/11/96 +1100, you wrote: >Hi ALl >anyone got any stats on the effect of air temperature of charge in FI >normally aspirated engines. > Doug this info is straight from Jeff Hartman's book "Fuel Injection installation, performance tuning, modifications" Page 64 chapter 7 for those who have the book. "each 11 degrees Farenheit increase reduces air density 1 percent" I'm new to the list but have learnt plenty just by reading Thanks to the person who recomended adding more advance to cure a cold running problem around 2000rpm worked like a charm for me too. I'd forgotten about this sneaky little table that lets you add ignition advance/ retard based on eng temp and was heading off in the wrong direction trying to cure it with more fuel. Jon Hanson Johannesburg South Africa. ------------------------------ End of DIY_EFI Digest V1 #342 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. A non-digest (direct mail) version of this list is also available; to subscribe to that instead, replace "diy_efi-digest" in the command above with "diy_efi".